Psychosis
In psychopathology, psychosis is the inability to distinguish what is or is not real. Examples of psychotic symptoms are delusions, hallucinations, and disorganized or incoherent thoughts or speech. Psychosis is a description of a person's state or symptoms, rather than a particular mental illness, and it is not related to psychopathy.
Common causes of chronic psychosis include schizophrenia or schizoaffective disorder, bipolar disorder, and brain damage. Acute psychosis can also be caused by severe distress, sleep deprivation, sensory deprivation, some medications, and drug use. Acute psychosis is termed primary if it results from a psychiatric condition and secondary if it is caused by another medical condition or drugs. The diagnosis of a mental-health condition requires excluding other potential causes. Tests can be done to check whether psychosis is caused by central nervous system diseases, toxins, or other health problems.
Treatment may include antipsychotic medication, psychotherapy, and social support. Early treatment appears to improve outcomes. Medications appear to have a moderate effect. Outcomes depend on the underlying cause.
Psychosis is not well-understood at the neurological level, but dopamine is known to play an important role. In the United States about 3% of people develop psychosis at some point in their lives. Psychosis has been described as early as the 4th century BC by Hippocrates and possibly as early as 1500 BC in the Ebers Papyrus.
Signs and symptoms
Hallucinations
A hallucination is defined as a sensory perception in the absence of external stimuli. Hallucinations are different from illusions and perceptual distortions, which are the misperception of external stimuli. Hallucinations may occur in any of the senses and take on almost any form. They may consist of simple sensations or more detailed experiences. Hallucinations are generally characterized as being vivid and uncontrollable. Auditory hallucinations, particularly experiences of hearing voices, are the most common and often prominent feature of psychosis.Up to 15% of the general population may experience auditory hallucinations. The prevalence of auditory hallucinations in patients with schizophrenia is generally put around 70%. Reported prevalence in bipolar disorder ranges between 11% and 68%. During the early 20th century, auditory hallucinations were second to visual hallucinations in frequency, but they are now the most common manifestation of schizophrenia, although rates vary between cultures and regions. Auditory hallucinations are most commonly intelligible voices. When voices are present, the average number has been estimated at three. Content, like frequency, differs significantly, especially across cultures and demographics. People who experience auditory hallucinations can frequently identify the loudness, location of origin, and may settle on identities for voices. Western cultures are associated with auditory experiences concerning religious content, frequently related to sin. Hallucinations may command a person to do something potentially dangerous when combined with delusions.
So-called "minor hallucinations", such as extracampine hallucinations, or false perceptions of people or movement occurring outside of one's visual field, frequently occur in neurocognitive disorders, such as Parkinson's disease.
Visual hallucinations occur in roughly a third of people with schizophrenia, although certain studies show rates higher than 60%, suggesting that the prevalence of visual hallucinations may be higher in certain samples than traditionally thought. The reported prevalence in bipolar disorder is around 15%. Content commonly involves animate objects, although perceptual abnormalities such as changes in lighting, shading, streaks, or lines may be seen. Visual abnormalities may conflict with proprioceptive information, and visions may include experiences such as the ground tilting. Lilliputian hallucinations are less common in schizophrenia, and are more common in various types of encephalopathy, such as peduncular hallucinosis.
A visceral hallucination, also called a cenesthetic hallucination, is characterized by visceral sensations in the absence of stimuli. Cenesthetic hallucinations may include sensations of burning, or re-arrangement of internal organs.
Delusions
A delusion is a fixed, false, idiosyncratic belief, which does not change even when presented with incontrovertible evidence to the contrary. Delusions are context- and culture-dependent: a belief that inhibits critical functioning and is widely considered delusional in one population may be common in another, or in the same population at a later time. Since normative views may contradict available evidence, a belief need not contravene cultural standards in order to be considered delusional. However, the DSM-5 considers a belief delusional only if it is not widely accepted within a cultural or subcultural context.Prevalence of delusions in schizophrenia is generally considered around 80-90%, according to Columbia University. A 2022 systematic review found a prevalence of around 70% in bipolar disorder.
The DSM-5 characterizes certain delusions as "bizarre" if they are clearly implausible, or are incompatible with the surrounding cultural context. The concept of bizarre delusions has many criticisms, the most prominent being that judging their presence is not highly reliable even among trained individuals.
A delusion may involve diverse thematic content. The most common type is a persecutory delusion, in which a person believes that an entity seeks to harm them. Others include delusions of reference, delusions of grandeur, thought broadcasting and thought insertion. A delusion may also involve misidentification of objects, persons, or environs that the afflicted should reasonably be able to recognize; such examples include Cotard's syndrome and clinical lycanthropy.
The subject matter of delusions seems to reflect the current culture in a particular time and location. For example, in the early 1900s in the United States, syphilis was a common theme in delusions. During the Second World War, it was Germany. In the Cold War era, communists became a frequent focus. Now, in recent years, technology is a common subject matter of delusions. Some psychologists, such as those who practice the Open Dialogue method, believe that the content of psychosis represents an underlying thought process, that may in part, be responsible for psychosis, though the accepted medical position is that psychosis is due to a brain disorder.
Historically, Karl Jaspers classified psychotic delusions into primary and secondary types. Primary delusions are defined as arising suddenly and not being comprehensible in terms of normal mental processes, whereas secondary delusions are typically understood as being influenced by the person's background or current situation.
Disorganized speech/thought and disorganized behavior
Disorganization is categorized into either disorganized speech, and grossly disorganized motor behavior. Disorganized speech or thought, also formally called thought disorder, is disorganization of thinking that is inferred from speech. Characteristics of disorganized speech include rapidly switching topics which is called derailment or loose association, switching to topics that are unrelated which is called tangential thinking, incomprehensible speech which is called incoherence and referred to as a word salad. Disorganized motor behavior includes repetitive, odd, or sometimes purposeless movement. Disorganized motor behavior rarely includes catatonia, and although it was a prominent symptom historically, it is rarely seen today. Whether this may be due to the use of historical treatments or the lack thereof is unknown.Catatonia describes a profoundly agitated state in which the experience of reality is generally considered impaired. There are two primary manifestations of catatonic behavior. The classic presentation is a person who does not move or interact with the world in any way while awake. This type of catatonia presents with waxy flexibility. Waxy flexibility is when someone physically moves part of a catatonic person's body and the person stays in the position even if it is bizarre and otherwise nonfunctional.
The other type of catatonia is more of an outward presentation of the profoundly agitated state described above. It involves excessive and purposeless motor behaviour, as well as an extreme mental preoccupation that prevents an intact experience of reality. An example is someone walking very fast in circles to the exclusion of anything else with a level of mental preoccupation that was not typical of the person prior to the symptom onset. In both types of catatonia, there is generally no reaction to anything that happens outside of them. It is important to distinguish catatonic agitation from severe bipolar mania, although someone could have both.